The present invention relates to fluid collection devices for sampling fluid from a patient. More specifically, the invention relates to such a device having a retractable needle feature for rendering the device non-reusable and safely disposable.
Various types of medical devices employ a needle for piercing the skin of a patient for diagnostic or therapeutic purposes. One such device is a phlebotomy or blood collection device that includes a needle for piercing a blood vessel of the patient to allow blood to be sampled from the patient. When the needle is inserted into the blood vessel of the patient, blood is withdrawn through the needle into a vacuum collection tube. Handling of such needle-bearing medical devices after the needle is withdrawn from the patient can result in transmission of various pathogens, most notably human immune virus (HIV), to uninfected medical personnel, due to an inadvertent needle stick.
Since the mid-1980s, concern over the risk of accidental needle stick injuries has spawned a number of design approaches for safety needle devices. Such devices can be broadly categorized as sliding sheath needle devices, wherein a physical barrier is positioned about the needle tip after use, and as needle-retraction devices, wherein the tip of the needle is retracted into the device after use.
The known devices suffer from one of several problems, including complicated structures that increase the cost of manufacturing the device. A safety needle product may be safe, but if it is too expensive, it will not be accepted, and the benefits of the safety product will never be recognized by the medical community. In addition, many devices require awkward or cumbersome actions to cause the needle to retract. The more complicated it is to retract a needle, the less likely it is that the medical professional will take the time to retract the needle, particularly in emergency situations.
In addition, in the field of phlebotomy, many of the known devices do not adequately protect against inadvertent contact with the non-patient tip of the needle. Since a person""s finger is generally smaller than the rearward opening of a phlebotomy device, the rearward end of the needle remains a safety concern after it has been contaminated with a patient""s blood. The known medical devices do not adequately address the protection needed to efficiently shield both the forward and rearward ends of the needle.
In light of the foregoing, the present invention provides a safety medical device having a retractable needle. The present invention is particularly suited for operation in connection with a fluid container such as a vacuum tube used for phlebotomy. The device includes a needle having a sharpened tip for piercing a patient. Preferably, the needle is double-ended having a rearward sharpened tip for piercing a seal on a fluid container. After use, the needle is retracted into the housing of the device so that the forward end of the needle is enclosed to prevent inadvertent contact with the contaminated needle.
The invention includes a biasing element such as a spring that biases the needle rearwardly toward the retracted position in which the needle is enclosed within the housing. The needle retainer releasably retains the needle against the bias of the spring so that the forward tip of the needle is exposed for use. After use, the medical professional actuates retraction to release the needle so that the spring displaces the needle rearwardly into the retracted position.
Another object of the invention is to provide a guide for guiding the needle when the needle is displaced between the projecting position and the retracted position. The guide includes at least one track and at least one guide tab connected with the needle, and projecting into operative engagement with the track. The track has an axial portion extending substantially parallel to the axis of the housing and a transverse portion extending transverse the axis of the barrel so that during retraction the needle is tilted so that the needle is disposed transverse the axis of the housing in the retracted position.
Yet another object of the invention is to provide a pocket for receiving and protecting the rearward sharpened tip of the needle when the needle is disposed in the retracted position. The pocket may be formed in a cylindrical insert that lines the housing. Preferably, the insert further includes a wing projecting forwardly and intersecting the guide. The wing has a lower edge configured in the shape of the transverse portion of the track, wherein the lower edge of the wing forms a sidewall of the transverse portion of the track.